We’ve all seen the social media memes suggesting that happiness is a choice. But if you’re struggling with a persistent low mood, you already know the truth: you can’t simply “willpower” your way back to joy.
Despite what wellness influencers might tell you, a lack of happiness isn’t a character flaw or a failure of attitude.
The reality is that your emotions aren’t just thoughts – they are driven by complex neurochemistry. When those “grey cloud” days follow you despite your best efforts to stay positive, it’s often because your brain’s biochemistry is overriding your mindset.
Understanding the biochemistry of emotions is the first step toward real relief. If you’ve ever felt like motivational quotes and “good vibes” aren’t enough, here is the scientific reason why your brain might be working against your best intentions.
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Neurotransmitters and neurons
Specifically, you’re feeling the ebb and flow of neurotransmitters like dopamine and serotonin, which dictate whether the world appears bright or feels heavy.
These chemical messengers – often referred to as “feel-good hormones” – are produced by the body and directly influence different organs, including our brain.
In their role as neurotransmitters, they carry messages across the spaces between nerve cells to enable them to “talk” to each other.
Our brain is basically a giant network of these nerve cells, called neurons. They don’t touch each other, and there’s a tiny gap between them called a synapse. A neurotransmitter’s job is to get a signal across the gap to tell the next neuron what to do.
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Feedback loop
How well these neurotransmitters work can make a big difference in how we feel from day to day, which is influenced by our hormone levels and balance.
Serotonin, made in the brain (10%) and gut (90%), works as our brain’s inner mood regulator. When levels are steady, we feel calm, content, and emotionally balanced. When they’re low, we can often feel anxious, irritable, or down.
Dopamine, made in the brain and adrenal glands, triggers the reward centres in our brains, giving us drive by fuelling motivation and focus.
These two hormones also interact and influence each other. For instance, healthy serotonin levels help regulate dopamine’s highs and lows, preventing extreme swings.
But if serotonin levels dip, dopamine-driven urges can feel more intense, which explains why we chase dopamine hits through compulsive social media scrolling, binge-watching series, or binge-eating sugary snacks when we’re feeling down.
However, when we spike dopamine after a rewarding activity, the brain adjusts receptors to prevent overload.
This is why overstimulation, like constantly checking your phone, can blunt dopamine sensitivity over time. Chronic stress can also reduce dopamine production and receptor sensitivity.
Making neurotransmitters
Serotonin and dopamine are both made from amino acids, which we get from food and supplements. Serotonin is made from the amino acid tryptophan and is converted to 5-HTP and then into serotonin, while dopamine is made from tyrosine.
As such, healthy hormone levels start with a balanced diet. You find tryptophan in foods like eggs, salmon, nuts, seeds and tofu. We get tyrosine from chicken, beef, dairy, beans, lentils, and soy.
You can also provide your body with additional support by ensuring your body gets vitamins and minerals that work as cofactors to boost serotonin or dopamine production naturally. Without these, the process can stall.
These important vitamins and minerals include:
- Vitamin B6: Essential for converting 5-HTP into serotonin, and L-DOPA into dopamine.
- Vitamin C: Needed for the step that converts dopamine into noradrenaline.
- Magnesium: Supports enzymes in these conversion processes, and also calms the nervous system.
- Folate (B9) & vitamin B12: Support the methylation cycle, which influences serotonin metabolism.
- Iron: Needed for tryptophan and tyrosine hydroxylase, the enzyme that starts the serotonin pathway, and turns tyrosine into L-DOPA.
- Vitamin D: Regulates tryptophan hydroxylase activity — one reason sunlight helps mood.
- Copper: Plays a role in the conversion of dopamine into noradrenaline.
- Zinc: Supports enzyme activity and receptor function.
- Omega-3s: The anti-inflammatory effects of omega-3s create a more favourable environment for the production and signalling of both serotonin and dopamine. These fats can also improve neurotransmitter receptor sensitivity in brain cells.
Lifestyle factors
While we cannot directly control our feelings through sheer willpower, we can influence the neurochemical environment that produces them.
The brain, for all its complexity, responds predictably to certain inputs, like sleep patterns, nutritional choices, physical movement, social connection, and sunlight exposure.
These lifestyle factors act as levers that directly affect neurotransmitter production and regulation.
Getting more sunlight, especially first thing in the morning, boosts serotonin by regulating our circadian rhythm (through the pineal gland, which converts serotonin into melatonin).
Stress management is also important because your body regulates levels of these hormones through the Hypothalamic-Pituitary-Adrenal (HPA) axis and the Hypothalamic-Pituitary-Thyroid (HPT) axis.
Chronic stress can throw these axes out of balance, reducing serotonin signalling and resulting in mood dysregulation. This is where activities like meditation, mindfulness, yoga and journaling can help to regulate these happy hormones.
Regular movement, particularly aerobic exercise like running or cycling, releases these ‘feel-good’ hormones – it’s why it’s often called the “runner’s high”. This effect is associated with a drop in stress hormone levels, which helps to improve mood and combat depression and stress.
The other important piece in the feel-good puzzle is getting enough quality sleep. During restorative deep sleep, serotonin receptors reset and become more sensitive, helping us feel calm and emotionally steady the next day.
Poor sleep or sleep deprivation can also desensitise the dopamine receptors in the brain’s reward and attention centres, which can lead to difficulty concentrating, lower motivation, and a reduced sense of pleasure from everyday activities.
Not getting enough REM sleep can also leave us restless and craving artificial dopamine hits, like sugar, caffeine, or social media.
And poor sleep patterns and bad bedtime habits mess with our circadian rhythm, which is regulated by dopamine – normally, dopamine levels rise in the morning to help us feel alert and motivated, then gradually decline at night so we can wind down.
Creating balance
Due to their interplay, it is impossible to focus on one hormone without considering the other.
Finding the sweet spot is about the right balance, and your daily habits, like regular movement, food, sunlight, sleep, and taking care of your mental health, are powerful levers to keep that balance in check.
Author: Pedro van Gaalen
When he’s not writing about sport or health and fitness, Pedro is probably out training for his next marathon or ultra-marathon. He’s worked as a fitness professional and as a marketing and comms expert. He now combines his passions in his role as managing editor at Fitness magazine.